Winch base



FIG. 1 is a top plan view of a winch base, showing our new design;

FIG. 2 is a top perspective view thereof; and,

FIG. 3 is a front elevational view thereof, wherein a rear elevational view, left side elevational view, and right side elevational view are identical thereto.

The broken lines in the drawings depict portions of the winch base that form no part of the claimed design. 

CLAIM The ornamental design for a winch base, as shown and described. 